JavaScript history Web Designing

JavaScript was first introduced by Netscape in Navigator 2.0, as a simple scripting language that could be embedded directly in web pages. Since then, JavaScript has evolved through five versions and is now codified in a standard. Note that the name of the language, JavaScript, is only coincidentally related to the Java programming language. Although JavaScript and Java share some similarity in syntax, you don't need to know anything about Java to learn JavaScript.

JavaScript has evolved from Version 1.0 in Navigator 2.0 to Version 1.5 in Netscape 6. Microsoft's name for its version of JavaScript is Jscript, and, for the most part, Jscript mirrors JavaScript's functionality, but also varies from version to version. At the time of this writing, the most widely supported version is 1.2, which is the basis of both Netscape's and Microsoft's 4.0 browser implementations. If you have a script that is written for an older version, say JavaScript 1.1, it will work fine with all of the newer versions. However, if you use features in a later version, say JavaScript 1.5, older browsers will not understand your scripts. Later, you'll learn how to use JavaScript to detect what browser is displaying your page, so you can customize your scripts to be backwards-compatible.

JavaScript (and Jscript) have also been standardized as ECMAScript (ECMA-262). Technically, JavaScript 1.5 is an implementation of the third version of the ECMAScript standard. Currently, both Netscape 6 and IE 5.5 support this standard version of JavaScript very well, and hopefully they will continue to agree in their support.

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